Obtaining zinc oxid from zinc ores and products.



D g giATlEle PATENT o itTttJEi WOLDEEEEAE HUBIIMEL .liND HENRY LIVING-STONE SULMAN, F LGNBQN, ENG-LAND, AQSEG'ETQEYB T0 THE ME'I'BiLS EXTHACTIQN CORPORATION LIMITED, OF LONDON,

ZEN

UHTEsZ-WZ'KNG' 5513i?! @Xlllll Flt-(fill ZINC ORE$ AN 1D. PEQBUCTS.

gfififi mg, 7 {specification of Letters Eatent. yet-tented Aug. lgifi Ho Brewing.

To all 'wliom it mm! conccmrf 1 Be known that, we, Women/EAR Hos uses,

Ph. D, e. citizen of the Swiss Republic, sml

HENRY Lwmss'roim SULMAN. a subject of the King oi England, loot :ees icliug in London, lluglsml, new invented certain new and useful impcovements iu @loteining Zinc Uxids from f liuc Products, of which the following; is a. specification.

This invention relates to improvements in the sepsietiou sud recovery of zinc from its ores, compcuutls enrl other products. In the previous patent application Serial No. 341,350., ci" H. L. Sulmsn, No. 875,865, January 7, process is clescrioecl in which such time its centeiuing zinc oxid ere treat-eel with -solutiou of sulfui'ous eciol so as to sl ts-is e solution of bisultite of zinc from which the zinc is precipitstecl as insoluble mouosulfite lo the edclition of zinc oxiil to the solution, engl the present invention relates to improves piocesses based on similar pi'iiiciples, I

Accessing to invention a process of sepu ratiog zinc f om ores or compounus consists m the etc if necessary voletilisiug trots the coasted or um'oastecl ore the zinccontents in the form of oxicl together with other metallic matters, collectinc; the product tl'ius blows oil, ti'esting it with soution of sulmrous 'ccirl so as to obtain e solutioc of bisulfite of zinc and pre'cipitntiugg the zinc as insoluble monosulfits which is calcined-i to procluce zinc oxitl. I

W h us it may be that there is suitor mesent for carrying out not suiiicieiot i the process sstisisctoirily. in such cases iron pyrites oz" otl'iei' ore rich in sulfur is ecltled to supply the il9/C6SS"" queutity of sulfur for sultuirous e the iron thus introduced seit'ves suitable flux for the subsequent smeiti the ore.

the lcacl contained in invention consists l blown oil? com of condensing chambers so that the zinc exicl coiulcusccl in the remote! l l practically free from i lntimation filed fio lember J, 1967. sex-tel Ho. 401,513.

tion of zinc bisuliite. As in the previous process of Sulman the zinc is dissolved as bisuliite by treating the material containing zinc oxid with a solution of sulfui'ous acid.

'A'ccoi'ing to this invention the zinc OXld contaminated wltlo lead and other substances containing Water and introducing the highly saturated solution of sulfurous acid into the hermetically closed vessels Where the dissolving of the zinc oxid takes place.

In the process of separating zinc from its ores as described above an important feature of the present invention consists in intro- (lucing the solution of ziuc loisulfite into a closed vesselencl precipitating the zinc as insoluble monosullite under reduced pres sure. .ln s. practical method of carrying this into effect, the solution of zinc bisulfito While in e finely divided condition is subjected to such it degree of vucu um that sulfurous acid is liberated therefrom and the zinc is precipitated as insoluble monosulfite Without the addition ot' other reagent. Jilteifnatively the precipitation of the zinc monosuliite from the solution of zinc bisullite is effected partly by the addition of zinc oxiclcnd partly by the application of a. vacuum to the" solution.

. .-Tl1o following is e description by Way of fuel whereupon air is blown througli'tlie heated mass; or alternatively, the roasted ore is iiiti'oilucetl iuto s :tumsce' WltiiOlli coal 22ml treated with loo-suing gas derived; from u,

pl'fltlllfifil. Or the sine cosy be volatilliy an electric ciu'reut. in any case the l ziiic is tlisiveu oil as osicl together with part of the lead and possibly other matters contained in the ore. This oxidis collected in a series of dues, condensing chambers or the like, and during the condensation a partial separation the zinc and lead takes place in the condensing chambers so that the remoter chambers contain a zinc oxid which is practically pure. v

The zinc oXid mixed with lead, etc, condensed in the first chambers is treated in hermetically closed barrels with water and sulfurous acid gas under pressure. By this means it is possible to use a very high proportion of sulfurous acid and therefore to obtain a rapid and efi'ective solution. Preterably the sulfurous acid derived from roasting the ore or otherwise is collected and pumped into a hermetically closed vessel containing water and the highly saturated solution of sulfurous acid thus obtained introduced into the hermetically closed barrels where the dissolving of the zinc oxid takes place.

' Other methods of applying the sulfurous acid under pressure could be adopted.

The contents of the extracting barrels, consisting of zinc bisulfite solution and an insoluble, residue containing lead, etc., are emptied into a number of air-tight columns or towers in which the residue is allowed to precipitate to the bottom while the zinc solution overflows near the top and is led into a second series of barrels, where by mixing .it with fresh zinc oxid (such for example as the purest zinc oXid from the condensing chambers) all the zinc is precipitated as monosulfite.

The time required for the precipitation of the zinc monosultite is considerably shortened and the zinc monosultite is much more perfectly precipitated if the operation is performed under reduced ')ressure. This can easily be carried into effect by connecting the precipitating barrel to a pump which removes the excess of snlfip'ous acid gas from the solution. It the re uction oi. pressure be suflicient, it is possible in certain cases to precipitate the zinc nionosulfite by the action of the vacuum alone without the addition of zinc oxid or other reagent. In order to releasethe sulfurous acid the zinc bisulfite can be reduced to a state of line subdivision as by spraying, under which conditions the action of the vacuum is lacilita'ted.

The precipitated zinc monosulfite collected in a vacuum tilter, a. filter press, a

centrifugal machine, or by other suitable IIIHUIS and is charged into a mull'le calciner \HIUIO the sulfurous acid is driven off andzinc oxid is obtained.

The residue from the extraction containin;: lead, etc., may be mixed for subsequent smelting with the bulk of the ore from which the zinc has been blown off or may be sep- :arately treated fortherecovery of the values it contains.

In certain cases it may not be necessary to roast the ore but itlmay be possible either by means of an electric furnace, by direct treatment in a converter with suitable fluxes or otherwise to volatilize the zinc oxid from the ore.

What we claim as our invention and desire to secure by Letters Patent is:

l. The herein described process for Ohtaining zinc oxid from zinc ores which consists in roasting the ore out of contact with the fuel volatilizing from the roasted ore the zinc contents in the form of dry oxid, together with other metallic matters, collecting thedry product thus, volatilized, treating it with a solution of sulturons acid. so as to obtain a solution of bisulfite of zinc, precipitating the zinc as insoluble monosul- 85 lite and calclning the monosulfite to produce zine oxid.

2. The-herein described process for obtaining zinc oxid from zinc ores which consists in. adding to the ore a preparation of another ore rich in sulfur, roasting the mixed ore, volatilizing from the roasted ore the zinc contents in the forinof oxid together with other metal ic matters, collecting the-i product thus volwtilized, treatinglit with a 95 solution of sulfurous acid so as. to obtain solution of bisulfite of zinc, precipitating the zinc as insoluble monosultitei'anti calcining the monosulfite to produce neibxid;

3. The herein described" process 'fbrroh tainingzinc oxid from zinc ores which consists in adding to the ore a preparation of iron pyrites, roasting the mixed ore, volatilizing from the roasted ore the zinc contents, in the form of oxid together with other Inetallie matters, collecting the product thus volatilized, treating it with a solution of suli'urous acid so as to obtain a solution of bisultite of zinc, precipitating the zinc as soluble monosulfite and calcining the mound ll sultite to produce zinc oXid.

v 4. The herein described process for tpb twining-Zine oxid from zinc ores which c'onsists in volatilizing the zinc contents from thegore in the form of oxid together with! 115 other metallic matters, collectin the Zinc oxid and other matters blown o from the ore in successive portions according to their .rateijof condensation so that a partial separatidri may take place,- treating the impure 120 zinc (5. id firstcondensed witha solution of sult'urt'nisacid so as to'obtaina solution of bisulfite of vzinc, adding to the solution of bisulfite thus obtained the purer zinc-oxid which condenseslast so as to precipitate the 125 zinc as ihonosulfite and calcining the monosulfite to reduce zinc oxid.

5. The erein described step in the process of obtaining zinc o'xid from zinc ores tainii g zinc oxid with a solution of sulfurous acid under pressure oontaming such a quantity of dissolved 'sulfurous acid as will dissolve the zinc. I p

6. The herein described process for obtaining zinc oxid from zinc ores which consists in roasting the ore, collecting the sulfurous acid thus obtained, pumping it into water under ressure, mixing the highly saturated solution of sulfurous acid with the material containing zinc oxid so as to obtain a'solution of bisulfite of zinc, precipitating the zinc as insoluble nionosulfite, and calcin' in the monosulfite to produce zinc oxid.

The herein described step in the proc ess of obtaining zinc oxid from zinc ores which consists in recipitating the insoluble zinc monosulfite rom the solution of zinc bisulfite under reduced pressure.

8 The herein described step in the process of obtaining zinc. oxid from zinc ores which consists 1n bringing the solution of zinc bisulfite into a finely divided condition and subjecting it to such a degree of vacuum that sulfurous acid is liberated therefrom and the zinc is precipitated as insoluble monosulfite.

9. The herein described process for obtaining zinc oxid from zinc ores which conmonosulfite and calcining t e monosulfite to produce zinc oxid.

10. The herein described process for obtaining zinc oxid from zinc ores which consists in volatili zing the zinc contents from the ore in the form of oxid together with other metallic matters, collecting the product thus volatilized, treating it-with a solution of sulfurous acid under pressure so as to obtain a solution of bisulfite of zinc, pre cipitating the zinc as insoluble monosu fite under a vacuum,'and calcining the monosulfite to produce zinc oxid. a

In testimony whereof we have signed our names to this specification in the presence of two subscribing witnesses.

WOLDEMMI. HOMMEL. HENRY LIVINGSTONE SULMAN.

Witnesses GEO. J. B. FRANKLIN, T. J. OSMAN I 

